a) Technical Field
The present invention relates to a method for manufacturing a signal line, a thin film transistor panel, and a method for manufacturing the thin film transistor panel.
(b) Discussion of the Related Art
An active matrix display device, such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display, and an electrophoretic display, may include a plurality of pixels arranged in a matrix and having an electric-field generating electrode and a switching element.
The switching elements for the display device may include a thin film transistor (TFT) having three terminals such a gate, a source, and a drain. Gate lines transmitting control signals for controlling the TFTs and data lines transmitting data signals to be supplied to the electric-field generating electrodes through the TFTs are also provided in the flat panel display. The thin film transistor of each pixel transmits or blocks a data signal transmitted to an electric-field, generating electrode from the source according to scanning signals transmitted to the gate. Also, the display includes a plurality of signal lines including a plurality of gate lines for transmitting the scanning signals and a plurality of data lines for transmitting the data signals.
The panel including the electric-field generating electrodes, the thin film transistors, and the signal lines is referred to as a thin film transistor panel.
The thin film transistor panel for the display device may have a layered structure including several conductive layers and insulating layers. The electric-field generating electrodes, the pate lines, and the data lines are formed in different layers and are insulated from each other by insulating layers.
To complete the thin film transistor panel having the layered structure, several photolithography processes including several photo steps and several etch steps are required for manufacturing an LCD panel. Since the production cost increases as the number of photolithography processes increases, reducing the number of photolithography processes reduces cost.
In addition to reducing the number of photolithography processes, there is a need to minimize the number of faulty display devices and maximize the aperture ratio of the pixels when simplifying the manufacturing process.